Killer Whales May Have Been Trapped by Climate Change

A pod of killer whales trapped in ice struggled to breathe before sea ice movement opened an escape route.

Credit: Screenshot of YouTube video.

Whale lovers around the world held their breath as a family of orcas, trapped in the ice of Canada's frozen Hudson Bay, were left with an ever-shrinking opening in the icy surface as their only breathing hole.

The two adult killer whales and nine younger orcas have now been freed by an apparent shift in the sea ice that trapped them, according to NBC News. It's believed that a change in the current within the bay broke open a path to the sea.

"When there is a new moon, the water current is activated. … It caused an open passage out to the open water," Petah Inukpuk, mayor of the nearby village of Inukjuak, told NBC News.

But what caused the pod of orcas to become trapped in the first place? Increasingly, experts are blaming climate change, which gave the orcas access to a place they normally abandon before winter. The trapped orcas were featured in a riveting online video, struggling for air inside an icy tomb that threatened to grow smaller with each passing hour. [Images: Rescuing Killer Whales]

In the past, the Arctic was covered with too much ice to make it hospitable for the killer whales, which prefer to live and hunt in open seas.

"The reason they can now access the Arctic is because there is a lot less ice because of global warming," Andrew Trites, director of the marine mammal research unit at the University of British Columbia, told the Toronto Star.

In fact, the Arctic sea-ice extent, or the area of ocean with at least 15 percent ice cover reached a new record low in September, dwindling to 1.32 million square miles (3.41 million square kilometers), according to the U.S. National Snow & Ice Data Center, which tracks sea ice with satellite data. As for the reason behind the ice melt, scientists have blamed both natural fluctuations and human-caused global warming.

This incident may be the first time killer whales have been seen in the region as late as January, Christian Ramp, a researcher with the Quebec-based Mingan Island Cetacean Study, told the Canadian Broadcasting Corp.

"It seems the ice dynamics are changing very quickly," said Ramp. Orcas generally hunt in the area during the summer months, then head to warmer waters before the Arctic ice moves in. But with climate change, Ramp said, the animals appear to be straying farther north and staying too late, the CBC reported.

According to Inukpuk, that region of the Hudson Bay typically would be completely frozen over by Halloween, according to the Star. But this year the bay didn't freeze until well after Christmas.

This isn't the first time the world has been transfixed by the plight of sea mammals. In 2005, a pod of six killer whales was trapped by sea ice in the shallow waters off Russia's eastern shore. Despite the efforts of local villagers, the animals — injured and bleeding from their own desperate attempts to free themselves — eventually died, according to the Associated Press.

And in 1988, there was an international effort to help three young gray whales trapped in the ice off Barrow, Alaska. Again, the locals responded to the animals' plight with chain saws, generators and water pumps, but in the brutal cold the sea froze over almost as quickly as it was opened up. One whale eventually died.

Finally, in a remarkable act of Cold War cooperation, a Soviet icebreaker succeeded in cutting a clear channel to the open ocean, freeing the two surviving whales. That incident was the basis for "Big Miracle," a film starring Drew Barrymore.

Marc Lallanilla has been a science writer and health editor at About.com and a producer with ABCNews.com. His freelance writing has appeared in the Los Angeles Times and TheWeek.com. Marc has a Master's degree in environmental planning from the University of California, Berkeley, and an undergraduate degree from the University of Texas at Austin.